1 /*
2 * Copyright (c) 2006 Paolo Abeni (Italy)
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote
15 * products derived from this software without specific prior written
16 * permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 *
30 * Bluetooth sniffing API implementation for Linux platform
31 * By Paolo Abeni <paolo.abeni@email.it>
32 *
33 */
34 #ifndef lint
35 static const char rcsid[] _U_ =
36 "@(#) $Header: /tcpdump/master/libpcap/pcap-bt-linux.c,v 1.15 2008-07-01 07:05:54 guy Exp $ (LBL)";
37 #endif
38
39 #ifdef HAVE_CONFIG_H
40 #include "config.h"
41 #endif
42
43 #include "pcap-int.h"
44 #include "pcap-bt-linux.h"
45 #include "pcap/bluetooth.h"
46
47 #ifdef NEED_STRERROR_H
48 #include "strerror.h"
49 #endif
50
51 #include <errno.h>
52 #include <stdlib.h>
53 #include <unistd.h>
54 #include <fcntl.h>
55 #include <string.h>
56 #include <sys/ioctl.h>
57 #include <sys/socket.h>
58 #include <arpa/inet.h>
59
60 #include <bluetooth/bluetooth.h>
61 #include <bluetooth/hci.h>
62
63 #define BT_IFACE "bluetooth"
64 #define BT_CTRL_SIZE 128
65
66 /* forward declaration */
67 static int bt_activate(pcap_t *);
68 static int bt_read_linux(pcap_t *, int , pcap_handler , u_char *);
69 static int bt_inject_linux(pcap_t *, const void *, size_t);
70 static int bt_setdirection_linux(pcap_t *, pcap_direction_t);
71 static int bt_stats_linux(pcap_t *, struct pcap_stat *);
72
73 /*
74 * Private data for capturing on Linux Bluetooth devices.
75 */
76 struct pcap_bt {
77 int dev_id; /* device ID of device we're bound to */
78 };
79
80 int
bt_findalldevs(pcap_if_t ** alldevsp,char * err_str)81 bt_findalldevs(pcap_if_t **alldevsp, char *err_str)
82 {
83 struct hci_dev_list_req *dev_list;
84 struct hci_dev_req *dev_req;
85 int i, sock;
86 int ret = 0;
87
88 sock = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
89 if (sock < 0)
90 {
91 /* if bluetooth is not supported this this is not fatal*/
92 if (errno == EAFNOSUPPORT)
93 return 0;
94 snprintf(err_str, PCAP_ERRBUF_SIZE,
95 "Can't open raw Bluetooth socket: %s", strerror(errno));
96 return -1;
97 }
98
99 dev_list = malloc(HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list));
100 if (!dev_list)
101 {
102 snprintf(err_str, PCAP_ERRBUF_SIZE, "Can't allocate %zu bytes for Bluetooth device list",
103 HCI_MAX_DEV * sizeof(*dev_req) + sizeof(*dev_list));
104 ret = -1;
105 goto done;
106 }
107
108 dev_list->dev_num = HCI_MAX_DEV;
109
110 if (ioctl(sock, HCIGETDEVLIST, (void *) dev_list) < 0)
111 {
112 snprintf(err_str, PCAP_ERRBUF_SIZE,
113 "Can't get Bluetooth device list via ioctl: %s",
114 strerror(errno));
115 ret = -1;
116 goto free;
117 }
118
119 dev_req = dev_list->dev_req;
120 for (i = 0; i < dev_list->dev_num; i++, dev_req++) {
121 char dev_name[20], dev_descr[30];
122
123 snprintf(dev_name, 20, BT_IFACE"%d", dev_req->dev_id);
124 snprintf(dev_descr, 30, "Bluetooth adapter number %d", i);
125
126 if (pcap_add_if(alldevsp, dev_name, 0,
127 dev_descr, err_str) < 0)
128 {
129 ret = -1;
130 break;
131 }
132
133 }
134
135 free:
136 free(dev_list);
137
138 done:
139 close(sock);
140 return ret;
141 }
142
143 pcap_t *
bt_create(const char * device,char * ebuf,int * is_ours)144 bt_create(const char *device, char *ebuf, int *is_ours)
145 {
146 const char *cp;
147 char *cpend;
148 long devnum;
149 pcap_t *p;
150
151 /* Does this look like a Bluetooth device? */
152 cp = strrchr(device, '/');
153 if (cp == NULL)
154 cp = device;
155 /* Does it begin with BT_IFACE? */
156 if (strncmp(cp, BT_IFACE, sizeof BT_IFACE - 1) != 0) {
157 /* Nope, doesn't begin with BT_IFACE */
158 *is_ours = 0;
159 return NULL;
160 }
161 /* Yes - is BT_IFACE followed by a number? */
162 cp += sizeof BT_IFACE - 1;
163 devnum = strtol(cp, &cpend, 10);
164 if (cpend == cp || *cpend != '\0') {
165 /* Not followed by a number. */
166 *is_ours = 0;
167 return NULL;
168 }
169 if (devnum < 0) {
170 /* Followed by a non-valid number. */
171 *is_ours = 0;
172 return NULL;
173 }
174
175 /* OK, it's probably ours. */
176 *is_ours = 1;
177
178 p = pcap_create_common(device, ebuf, sizeof (struct pcap_bt));
179 if (p == NULL)
180 return (NULL);
181
182 p->activate_op = bt_activate;
183 return (p);
184 }
185
186 static int
bt_activate(pcap_t * handle)187 bt_activate(pcap_t* handle)
188 {
189 struct pcap_bt *handlep = handle->priv;
190 struct sockaddr_hci addr;
191 int opt;
192 int dev_id;
193 struct hci_filter flt;
194 int err = PCAP_ERROR;
195
196 /* get bt interface id */
197 if (sscanf(handle->opt.source, BT_IFACE"%d", &dev_id) != 1)
198 {
199 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
200 "Can't get Bluetooth device index from %s",
201 handle->opt.source);
202 return PCAP_ERROR;
203 }
204
205 /* Initialize some components of the pcap structure. */
206 handle->bufsize = handle->snapshot+BT_CTRL_SIZE+sizeof(pcap_bluetooth_h4_header);
207 handle->offset = BT_CTRL_SIZE;
208 handle->linktype = DLT_BLUETOOTH_HCI_H4_WITH_PHDR;
209
210 handle->read_op = bt_read_linux;
211 handle->inject_op = bt_inject_linux;
212 handle->setfilter_op = install_bpf_program; /* no kernel filtering */
213 handle->setdirection_op = bt_setdirection_linux;
214 handle->set_datalink_op = NULL; /* can't change data link type */
215 handle->getnonblock_op = pcap_getnonblock_fd;
216 handle->setnonblock_op = pcap_setnonblock_fd;
217 handle->stats_op = bt_stats_linux;
218 handlep->dev_id = dev_id;
219
220 /* Create HCI socket */
221 handle->fd = socket(AF_BLUETOOTH, SOCK_RAW, BTPROTO_HCI);
222 if (handle->fd < 0) {
223 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
224 "Can't create raw socket: %s", strerror(errno));
225 return PCAP_ERROR;
226 }
227
228 handle->buffer = malloc(handle->bufsize);
229 if (!handle->buffer) {
230 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't allocate dump buffer: %s",
231 pcap_strerror(errno));
232 goto close_fail;
233 }
234
235 opt = 1;
236 if (setsockopt(handle->fd, SOL_HCI, HCI_DATA_DIR, &opt, sizeof(opt)) < 0) {
237 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
238 "Can't enable data direction info: %s", strerror(errno));
239 goto close_fail;
240 }
241
242 opt = 1;
243 if (setsockopt(handle->fd, SOL_HCI, HCI_TIME_STAMP, &opt, sizeof(opt)) < 0) {
244 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
245 "Can't enable time stamp: %s", strerror(errno));
246 goto close_fail;
247 }
248
249 /* Setup filter, do not call hci function to avoid dependence on
250 * external libs */
251 memset(&flt, 0, sizeof(flt));
252 memset((void *) &flt.type_mask, 0xff, sizeof(flt.type_mask));
253 memset((void *) &flt.event_mask, 0xff, sizeof(flt.event_mask));
254 if (setsockopt(handle->fd, SOL_HCI, HCI_FILTER, &flt, sizeof(flt)) < 0) {
255 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
256 "Can't set filter: %s", strerror(errno));
257 goto close_fail;
258 }
259
260
261 /* Bind socket to the HCI device */
262 addr.hci_family = AF_BLUETOOTH;
263 addr.hci_dev = handlep->dev_id;
264 #ifdef SOCKADDR_HCI_HAS_HCI_CHANNEL
265 addr.hci_channel = HCI_CHANNEL_RAW;
266 #endif
267 if (bind(handle->fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
268 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
269 "Can't attach to device %d: %s", handlep->dev_id,
270 strerror(errno));
271 goto close_fail;
272 }
273
274 if (handle->opt.rfmon) {
275 /*
276 * Monitor mode doesn't apply to Bluetooth devices.
277 */
278 err = PCAP_ERROR_RFMON_NOTSUP;
279 goto close_fail;
280 }
281
282 if (handle->opt.buffer_size != 0) {
283 /*
284 * Set the socket buffer size to the specified value.
285 */
286 if (setsockopt(handle->fd, SOL_SOCKET, SO_RCVBUF,
287 &handle->opt.buffer_size,
288 sizeof(handle->opt.buffer_size)) == -1) {
289 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
290 "SO_RCVBUF: %s", pcap_strerror(errno));
291 goto close_fail;
292 }
293 }
294
295 handle->selectable_fd = handle->fd;
296 return 0;
297
298 close_fail:
299 pcap_cleanup_live_common(handle);
300 return err;
301 }
302
303 static int
bt_read_linux(pcap_t * handle,int max_packets,pcap_handler callback,u_char * user)304 bt_read_linux(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user)
305 {
306 struct cmsghdr *cmsg;
307 struct msghdr msg;
308 struct iovec iv;
309 ssize_t ret;
310 struct pcap_pkthdr pkth;
311 pcap_bluetooth_h4_header* bthdr;
312
313 bthdr = (pcap_bluetooth_h4_header*) &handle->buffer[handle->offset];
314 iv.iov_base = &handle->buffer[handle->offset+sizeof(pcap_bluetooth_h4_header)];
315 iv.iov_len = handle->snapshot;
316
317 memset(&msg, 0, sizeof(msg));
318 msg.msg_iov = &iv;
319 msg.msg_iovlen = 1;
320 msg.msg_control = handle->buffer;
321 msg.msg_controllen = handle->offset;
322
323 /* ignore interrupt system call error */
324 do {
325 ret = recvmsg(handle->fd, &msg, 0);
326 if (handle->break_loop)
327 {
328 handle->break_loop = 0;
329 return -2;
330 }
331 } while ((ret == -1) && (errno == EINTR));
332
333 if (ret < 0) {
334 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
335 "Can't receive packet: %s", strerror(errno));
336 return -1;
337 }
338
339 pkth.caplen = ret;
340
341 /* get direction and timestamp*/
342 cmsg = CMSG_FIRSTHDR(&msg);
343 int in=0;
344 while (cmsg) {
345 switch (cmsg->cmsg_type) {
346 case HCI_CMSG_DIR:
347 memcpy(&in, CMSG_DATA(cmsg), sizeof in);
348 break;
349 case HCI_CMSG_TSTAMP:
350 memcpy(&pkth.ts, CMSG_DATA(cmsg),
351 sizeof pkth.ts);
352 break;
353 }
354 cmsg = CMSG_NXTHDR(&msg, cmsg);
355 }
356 if ((in && (handle->direction == PCAP_D_OUT)) ||
357 ((!in) && (handle->direction == PCAP_D_IN)))
358 return 0;
359
360 bthdr->direction = htonl(in != 0);
361 pkth.caplen+=sizeof(pcap_bluetooth_h4_header);
362 pkth.len = pkth.caplen;
363 if (handle->fcode.bf_insns == NULL ||
364 bpf_filter(handle->fcode.bf_insns, &handle->buffer[handle->offset],
365 pkth.len, pkth.caplen)) {
366 callback(user, &pkth, &handle->buffer[handle->offset]);
367 return 1;
368 }
369 return 0; /* didn't pass filter */
370 }
371
372 static int
bt_inject_linux(pcap_t * handle,const void * buf,size_t size)373 bt_inject_linux(pcap_t *handle, const void *buf, size_t size)
374 {
375 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "inject not supported on "
376 "bluetooth devices");
377 return (-1);
378 }
379
380
381 static int
bt_stats_linux(pcap_t * handle,struct pcap_stat * stats)382 bt_stats_linux(pcap_t *handle, struct pcap_stat *stats)
383 {
384 struct pcap_bt *handlep = handle->priv;
385 int ret;
386 struct hci_dev_info dev_info;
387 struct hci_dev_stats * s = &dev_info.stat;
388 dev_info.dev_id = handlep->dev_id;
389
390 /* ignore eintr */
391 do {
392 ret = ioctl(handle->fd, HCIGETDEVINFO, (void *)&dev_info);
393 } while ((ret == -1) && (errno == EINTR));
394
395 if (ret < 0) {
396 snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
397 "Can't get stats via ioctl: %s", strerror(errno));
398 return (-1);
399
400 }
401
402 /* we receive both rx and tx frames, so comulate all stats */
403 stats->ps_recv = s->evt_rx + s->acl_rx + s->sco_rx + s->cmd_tx +
404 s->acl_tx +s->sco_tx;
405 stats->ps_drop = s->err_rx + s->err_tx;
406 stats->ps_ifdrop = 0;
407 return 0;
408 }
409
410 static int
bt_setdirection_linux(pcap_t * p,pcap_direction_t d)411 bt_setdirection_linux(pcap_t *p, pcap_direction_t d)
412 {
413 p->direction = d;
414 return 0;
415 }
416